Talking to Lender (mortgagee) of Property Owner

[Mario Teran]

Good Morning, 

I am looking at potentially buying a two-fam for a full gut and rehab. One potential option to obtain the property is to assume the mortgage. The mortgage was modified a few years ago and it's currently a 40-year loan with favorable terms. The assessing dept has the property owner as the bank although the owner stated that he settled this issue with the loan mod. It could be the assessing data was not updated. My partner and I think it would be a good idea to speak directly with the lender (mortgagee). We would need to get authorization from the owner. What reasons could we give the owner that would justify granting us this authority? 

Thx